Not every AI recommendation market is locked down. In Two Filters, One Invisible Wall, we showed that AI recommendations operate through two filters: entry (AI Visibility Rate) and concentration (Gini coefficient). In Same GEO Playbook, Different Results, we demonstrated that identical GEO strategies produce 2x different outcomes depending on category structure. The natural next question: which categories are still open — and how much time is left? We classified all 10 software categories that DecaGEO tracks into two groups based on current structural data. The answer is concrete: 4 categories are still structurally open for new brands to gain meaningful AI recommendation share. 6 have already concentrated to the point where breaking in requires fundamentally different strategies.Documentation Index
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The classification: open vs. closed
A category is “open” when both filters are relatively permissive: a reasonable AI Visibility Rate (brands can get into recommendations) and a low Gini coefficient (recommendation weight isn’t locked into a few incumbents). A category is “closed” when one or both filters are restrictive. We draw the line at Gini 0.65. Below that threshold, the weight distribution is flat enough that new entrants can gain meaningful share through standard GEO efforts. Above it, the incumbents hold structural advantages that require specialized strategies to overcome. “Open” and “closed” are not binary absolutes. They describe the current structural difficulty of gaining meaningful AI recommendation share. Categories near the threshold — such as SEO (0.632) and Project Management (0.654) — should be treated as transitional markets.The 4 open categories
| Category | Gini | AI Visibility Rate | Brands for 80% | Why it’s open |
|---|---|---|---|---|
| Email Marketing | 0.568 | 8.4% | 15 (35.7%) | Lowest concentration of all 10 categories; top 3 hold only 25.8% of DECA |
| GEO | 0.572 | 43.5% | 59 (40.1%) | Highest visibility rate by far; category still forming; 147 brands recommended |
| Marketing Automation | 0.601 | 7.1% | 12 (34.3%) | Moderate concentration; top 3 hold 29.6%, leaving room for movement |
| SEO | 0.632 | 7.3% | 19 (33.3%) | Border case; Gini approaching threshold but still below 0.65 |
The 6 closed categories
| Category | Gini | AI Visibility Rate | Brands for 80% | Why it’s closed |
|---|---|---|---|---|
| CRM | 0.757 | 3.5% | 7 (19.4%) | Highest concentration; top 3 hold 54% of all DECA |
| Help Desk | 0.751 | 8.4% | 9 (21.4%) | Second-highest concentration; top 3 hold 46.6% |
| Influencer Marketing | 0.722 | 12.4% | 10 (22.2%) | High concentration despite higher visibility rate |
| AI Image Generators | 0.698 | 6.4% | 7 (28.0%) | Small category, high concentration; top 3 hold 55.9% |
| AI Writing Assistants | 0.662 | 4.1% | 15 (30.6%) | Very low visibility rate combined with moderate concentration |
| Project Management | 0.654 | 6.7% | 12 (27.9%) | Just above threshold; moderate concentration with low visibility |
What makes a category close?
Three forces push categories from open to closed over time: Signal accumulation. AI forms preferences by learning from data: reviews, comparisons, expert analyses, product documentation. The more data AI has about a category, the stronger its preferences become. CRM has 30+ years of accumulated signal. GEO has less than 2 years. Winner reinforcement. AI recommendations create a feedback loop. Brands that AI recommends get more attention, which generates more content about those brands, which AI then learns from — further reinforcing the recommendation. In Email Marketing, the loop is weaker because no brand has achieved the same dominance as HubSpot in CRM. Category definition convergence. Young categories have fuzzy boundaries. As a category matures, its boundaries sharpen. AI learns which products are “really” in the category and which are adjacent. This exclusion process reduces the AI Visibility Rate and increases concentration among survivors.The timeline question: how fast do windows close?
| Category | Current Gini | Direction | Estimated window |
|---|---|---|---|
| GEO | 0.572 | Rising | 12–24 months before reaching Oligopoly threshold (0.65) |
| Email Marketing | 0.568 | Stable/slow rise | 18–36 months; mature category, concentration has plateaued |
| Marketing Automation | 0.601 | Rising | 6–18 months; already approaching threshold |
| SEO | 0.632 | Rising | 3–12 months; closest to threshold among open categories |
Key finding: All 4 open categories are more likely to concentrate than to become more open as signal accumulates. The windows are open now, but none of them are opening wider.
Practical decision rule: If your category is open, prioritize speed: build category association before AI preferences harden. If your category is near the threshold, prioritize urgency. If your category is closed, prioritize arbitrage: niche prompts, adjacent categories, and platform diversification.
What “open” actually means for practitioners
Email Marketing (Gini 0.568)
The most open category by concentration. 15 brands needed for 80% of weight, top 3 hold only 25.8%. A brand currently ranked 10–15 may have a realistic path toward the top 5 through consistent GEO effort over 3–6 months. Specific opportunity: Mid-tier platforms with strong niche positioning (e-commerce, B2B, creator economy) have the most room to grow.GEO (Gini 0.572)
Highest AI Visibility Rate (43.5%) of any tracked category — AI recommends 147 out of 338 listed products. AI hasn’t formed strong exclusion preferences yet. Specific opportunity: Brands that establish clear, consistent definitions of what GEO means and position themselves as central to that definition will benefit as AI’s understanding of the category solidifies.Marketing Automation (Gini 0.601)
Approaching the threshold but still below it. Top 3 hold 29.6%, leaving room for brands ranked 4–12 to gain meaningful share. Specific opportunity: Clear subcategories (email automation, workflow automation, lead scoring) create niche entry points before competing for generic recommendations.SEO (Gini 0.632)
The closest to the threshold and least open of the four. Top 3 hold 35.4%, 19 brands needed for 80% weight. Specific opportunity: Brands that generate differentiated signal — original research, unique datasets, novel methodologies — can still shift position because AI values diverse signal types.What “closed” means — and what to do anyway
Being in a closed category isn’t a death sentence. GEO strategy must shift from direct competition to structural arbitrage. Niche-first approach. In CRM (Gini 0.757), generic slots are locked. But niche prompts — “best CRM for real estate teams,” “CRM for solo consultants” — have less entrenched competition. Cross-category signal building. A CRM with strong project management features should build signal in Project Management (Gini 0.654) rather than fighting directly in CRM. Cross-category signal influences how AI understands the brand’s broader relevance. Platform diversification. Concentration patterns vary by AI platform. A category that’s Monopoly-concentrated on ChatGPT may be more distributed on Perplexity, Claude, or Gemini. Differentiation frame creation. Instead of competing on existing dimensions, create new comparison frames (“most privacy-focused CRM”) where incumbents have less established signal.The strategic priority: timing
For brands in open categories, GEO investment has a time-limited window of high ROI. Every month that passes without action is a month where competitors are generating signal and AI is forming preferences. As Gini rises:- The number of brands that can capture meaningful recommendation share shrinks
- The amount of signal needed to shift position increases
- The ROI of standard GEO efforts declines
Key takeaway: Of 10 software categories tracked, 4 are structurally open (Gini below 0.65) and 6 are structurally closed (Gini 0.65 or above). All open categories have structural reasons to concentrate further. For brands in open categories, the GEO investment window is measured in months, not years. For brands in closed categories, the strategy must shift to niche targeting, cross-category signal building, and platform diversification.
Methodology
Data source: DecaGEO AI recommendation tracking. Hundreds of recommendation-seeking prompts sent to ChatGPT (GPT-5.4) weekly, US region. Data from the week of May 17, 2026. Classification threshold: Gini 0.65 is used to separate “open” from “closed” categories, based on natural clustering in the 10-category dataset. Timeline estimates: Based on structural indicators (category age, investment intensity, adjacent category maturity) rather than longitudinal tracking. G2 listing counts: Retrieved from G2.com category pages on May 19, 2026. Limitations: Classification is based on a single snapshot. The Gini 0.65 threshold is descriptive and may be refined. Timeline estimates are directional, not predictive. Data reflects one AI platform (ChatGPT) in one region (US).FAQ
What does it mean for a category to be open?
What does it mean for a category to be open?
An open category has a Gini coefficient below 0.65, meaning AI recommendation weight is relatively distributed across brands. Standard GEO efforts — brand definition consistency, third-party mentions, structured data — produce measurable results because the weight distribution has room for new entrants to gain share.
Which open category should I prioritize first?
Which open category should I prioritize first?
Prioritize the category where your brand has the strongest combination of product relevance, current AI visibility, and speed of closure. SEO is closest to the threshold; Marketing Automation is approaching it; Email Marketing and GEO have more runway. The best first target is the category where your brand can build credible signal before the window closes.
What should I do in the first 90 days if my category is open?
What should I do in the first 90 days if my category is open?
(1) Audit how AI currently describes your brand and competitors. (2) Fix brand definition consistency across your website, review profiles, and documentation. (3) Publish comparison, alternative, and use-case pages tied to high-value prompts. (4) Earn third-party mentions in category-relevant sources. (5) Track generic, niche, and comparison prompts weekly. The goal is to become a default consideration before AI recommendation preferences harden.
What should I do if my category is already closed?
What should I do if my category is already closed?
Focus on structural arbitrage: niche-first targeting, cross-category signal building, platform diversification, and differentiation-frame creation. Do not start by trying to win generic category prompts. Find pockets of recommendation demand where AI has weaker or less stable preferences.
Should I wait to start GEO if my category is already closed?
Should I wait to start GEO if my category is already closed?
No. Even in closed categories, viable strategies exist — they’re just different from the standard playbook. Waiting only makes the problem worse, as concentration tends to increase over time.
Why is GEO the most open category?
Why is GEO the most open category?
GEO’s openness is a function of its youth. The category has existed for less than 2 years, so AI hasn’t accumulated enough signal to form strong preferences. Additionally, GEO’s boundaries are fuzzy — it overlaps with SEO, content optimization, and AI analytics — which inflates the AI Visibility Rate. Both factors are temporary.
Can a closed category become open again?
Can a closed category become open again?
Theoretically yes, if a major disruption reshuffles the landscape. In practice, structural forces favor increasing concentration as categories mature. No category in our dataset has shown movement from closed to open.
How often will this classification be updated?
How often will this classification be updated?
DecaGEO tracks AI recommendations weekly. Category classifications will be updated as Gini coefficients shift. Significant changes — such as a category crossing the 0.65 threshold — will be reported in analysis updates.
Sources
- DecaGEO AI recommendation tracking data, week of May 17, 2026. ChatGPT (GPT-5.4), US region.
- G2.com category listing counts, retrieved May 19, 2026.
- DecaGEO, “Two Filters, One Invisible Wall,” May 2026.
- DecaGEO, “Same GEO Playbook, 2x Different Results,” May 2026.
- DecaGEO, “AI Visibility Rate: Why AI Ignores Most Software,” May 2026.